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+-- Thread: Cleaning a cistern??? (/showthread.php?tid=7133441)
Cleaning a cistern??? - Phil S. - 11-01-2015
I need some help fellas. I have a 3000 gallon cistern that provides water for my house via rainwater catchment. It's 12' in diameter and about 4-1/2' deep. I'm trying to figure a way to clean it that doesn't require it be completely drained (leaving us without water until we get enough rain to fill it again) and I'd like to avoid climbing in to it so I don't accidentally damage the liner. I only have access to the tank at one point, a 2' X 3' hatch at one side. I've been thinking of some sort of venturi swimming pool vac with a wand long enough to reach the far side of the tank. Anybody have experience with such a tool or any suggestions of a better way to proceed? Not hoping for spotless, but just getting the visible accumulation of algae or whatever the aquatic dust bunnies are rolling around in the tank.
Phil
Re: Cleaning a cistern??? - MsNomer - 11-01-2015
Cistern water tastes better with frogs in it. Personal experience--my brother and I put them there.
Seriously, consider that whatever you do will stir things up. Our cistern in Mississippi (read warm year-round) was covered only with rough loose boards. It gave fine drinking water until it developed a leak about 40 years later.
Re: Cleaning a cistern??? - crokett™ - 11-01-2015
I'm wondering if a pool pump/filter setup would work. Just pump the water out, filter it and return it to the cistern. From personal experience a venturi swimming pool vac is one step from useless. If you want to vacuum it, hook the pool vac up to a pool filter.
Re: Cleaning a cistern??? - Phil S. - 11-01-2015
A friend thought his cistern water tasted a bit off. Found a moldy dead mink floating in it - YEEEEEEEEEEEEEEEEEEECH!
I haven't had that problem --- yet.
Re: Cleaning a cistern??? - Phil S. - 11-01-2015
Not surprised by your opinion. The photos I see of venturi pumps look pretty mickey mouse. I have the cistern set up where I can recirculate water through a standard house sediment filter, similar to this and back into the tank. The pump in my system doesn't move enough water to collect anything any distance from the inlet. I like the idea of recycling the water back into the tank, but I suspect it wouldn't take long and the visibility would go to zero. Now I'm thinking possibly:
1) a two step approach - pump, filter and direct back into the tank and when visibility gets too bad quit and let it settle, repeat until happy, or
2) pump the worst of it straight outside, stir up the fines and recycle through the whole house filter to clear most of the rest.
Seems maybe the second approach may be the most efficient, getting rid of the worst of it most quickly without going through a ton of filters, but I'll lose more water.
Food for thought. Thanks!
Re: Cleaning a cistern??? - Foggy - 11-01-2015
Algae eating fish??
Re: Cleaning a cistern??? - Phil S. - 11-01-2015
Maybe I could get some of those hopping carp I hear about. Be tough to keep them in the tank though and ADF&G would shoot me.
Re: Cleaning a cistern??? - crokett™ - 11-01-2015
A couple hundred bucks for a pool pump and sand filter would have that cistern clear in a relatively short amount of time. The only problem is the filter would clog and need cleaning. You'd be wasting some of the water on backwashing. A more effective filter would be a DE filter.
Re: Cleaning a cistern??? - meackerman - 11-01-2015
my sand filter doesn't take much backwashing to clean it, as long as I don't let it get bad.
Re: Cleaning a cistern??? - Mr_Mike - 11-02-2015
Is cleaning a cistern even a thing? If so, I'd guess there are pros that do it. Find out what they do and do it.
Using a pool pump and mechanical filter won't do much unless you kill the algae or other growth that is there. You can't get it all and it will grow back quick. Algae requires sunlight, so I have no idea what might actually be growing. I don't think this is a fruitful venture.